Product Introduction

The construction quality of direct-buried steam pipelines is crucial. Every production process must be strictly controlled, quality must be thoroughly inspected, and implementation must follow design requirements. Especially for joint insulation construction, strict control and individual inspection are necessary to ensure construction quality.
2. Necessary measures must be taken during the rainy season to prevent flooding and pipe flotation. Once insulation materials get wet, it will be difficult to completely remove the water, which greatly reduces insulation effectiveness, increases heat loss, and may cause damage or rupture to the insulated pipes.
3. To ensure construction quality, welds should be initially welded with argon arc welding and the main pipeline should undergo flaw detection.
4. Before pipeline trial operation, the trench must be backfilled to ensure sufficient friction between the insulation layer's outer shell and the soil, preventing the insulation layer from being damaged due to expansion and contraction along with the inner steel pipe.
5. Strict initial operation procedures must be followed. During operation, ensure the pipe warming time because steam temperature is high. The pipeline must be heated slowly to allow the pipe and insulation layer to separate smoothly and avoid insulation damage. Since the insulation layer is moist, slow heating allows moisture to be evenly expelled through the vent pipe, preventing insulation layer bursting. When the vent pipe releases almost no gas, the steam supply can be increased gradually until reaching the operating load. The figure shows our company's pipe warming and temperature maintenance curve.
Additionally, before steam introduction, condensate in the steam pipeline network must be fully drained. During operation, fluctuations in thermal load magnitude and frequency should be minimized.
Regularly check the drainage devices to ensure condensate flows smoothly and avoid water hammer. Water hammer not only damages compensators but also causes insulation structure damage due to strong vibrations. This occurs because when thermal load changes significantly in magnitude and frequency, thermal displacement varies frequently. Using composite insulation pipes increases friction between the working pipe and inner insulation material. According to relevant data, over a 16-year thermal network lifespan, friction between the working pipe and inner insulation layer can reach 15,000 to 20,000 times. Generally, rigid insulation materials cannot withstand such repeated wear, especially due to the pipe's own weight causing more severe friction at the bottom. Improper handling will damage the insulation structure's performance and reduce the insulation pipe's lifespan. (8) All pipeline components and supports must be purchased from units approved by the national special equipment safety supervision department and must have product quality certificates, installation and maintenance instructions, and supervision and inspection documents. Their quality must not be lower than the current national standards.
(9) Pipeline installation should only proceed after the following conditions are met: civil engineering inspection is qualified and installation requirements are satisfied; pipeline components and supports have passed inspection; pipes, fittings, valves, and other internal parts are cleaned.